Polymers of carbon monoxide and ethylenically unsaturated hydrocarbons, commonly called polyketones, have been known and available in limited quantities for many years. For example, polymers of ethylene or ethylene-propylene which contain small quantities of carbon monoxide are disclosed in U.S. Pat. No. 2,495,286, prepared using free radical catalysts. British Patent No. 1,081,304 discloses polymers containing higher concentrations of carbon monoxide prepared using alkylphosphine complexes of palladium salts as catalysts. A special class of linear polyketones is disclosed in U.S. Pat. No. 3,694,412, wherein the monomer units of carbon monoxide and ethylenically unsaturated hydrocarbons occur in alternating order.
High molecular weight linear alternating polyketones are of considerable interest because they exhibit good physical properties. These polymers can be represented by units of the repeating formula ##STR1## wherein A is the moiety obtained by the polymerization of an ethylenically unsaturated hydrocarbon through the ethylenic unsaturation. A general process for preparing such linear alternating polymers is disclosed, for example, in published European Patent Applications Nos. 121,965 and 181,014. The process comprises contacting the monomers in the presence of a catalyst obtained from a compound of palladium, cobalt or nickel, the anion of a non-hydrohalogenic acid having a pKa less than about 2, and a bidentate ligand of phosphorus, arsenic or antimony. The resulting linear alternating polymers are generally high molecular weight engineering thermoplastics that possess a balance of properties comprising strength, stiffness, impact resistance, and dimensional stability. Such thermoplastics are useful as structural materials and in the production of articles for food and drink containers. Engineering thermoplastics are especially attractive as replacements for metals because of the reduction in weight that can often be achieved as, for example, in automotive applications.
For a particular application, a single thermoplastic, such as high molecular weight linear alternating polyketone, may not offer a particular combination of desired properties. One particularly appealing method of obtaining such advantages is through blending together two or more thermoplastic polymers to give a material with a different combination of properties. Although polyketones have many desirable properties it would be advantageous to have polymeric compositions exhibiting modified properties.